Living fossils can be a foreign concept to some, as well as an oxymoron, but they do exist! Living fossils describe living species that look similar to ancient species that have only been seen through fossil records. Many of these living fossils have survived major extinction events and have ancestral lineage that can date back millions of years. Living fossils are fascinating creatures to learn about – check out some of them below.

A fish with legs?

This amazing specimen was dubbed the ‘most important zoological find of the century’, and the species is a member of an ancient lineage that has been around for over 360 million years. Coelacanth were thought to have died out with the dinosaurs, but were miraculously rediscovered by scientists in 1938.

They can be found on every continent except for Antarctica, spanning about 2m long and living in depths of 150m to 700m. Sometimes they can be spotted swimming in a “headstand” posture which scientists attribute to their sensitivity to light or electromagnetic fields in submarine caves. There is also ongoing controversy as to whether coelacanths are the closest living relatives of the first species to walk on land.

Dawn of the redwood

Considered one of the greatest botanical finds of the 20thcentury, the dawn redwood was known only from ancient fossils, until a small population was discovered in the forests of Central China in 1944.

The dawn redwood is a very prominent tree found in Asia, reaching up to 46m (150ft) in height and boasting a thick trunk and broad buttressed base. The good news is that it’s a monoecious species, meaning it can self-pollinate and reproduce. The bad news is that fast-developing urban areas in places like China pose a huge threat to its survival.

Best hiking partner

Mountain tapirs are endemic to the Andes in South America. These agile, sure-footed mountain climbers are the smallest of the four surviving species of tapir that represent the remnants of a lineage that evolved around 55 million years ago, after the demise of the dinosaur.

The mountain tapir’s woolly appearance makes it my pick for cutest “living fossil” in ARKive. – this is one dinosaur I would not mind wallowing in the mud with.

Sand digging helps support the ecosystem?

Horseshoe crabs may not be aware of this, but every time they dig for food, they are aerating the substrate, the earthy material that exists in the bottom of a marine habitat, resulting in a higher level of species richness. Their eggs are also a vital source of food for sea turtles, alligators and fish. Species almost identical to the horseshoe crab existed 230 million years ago in the Triassic period.

Despite their name, horseshoe crabs are not crabs at all. They are a part of the arachnid family (spiders, scorpions, ticks, and mites), possessing six appendages to help them walk and eat. They also have blue copper-based blood!

If the ice is breathing, it’s probably this guy

The iconic American alligator is a “living fossil” that has remained on Earth in its same form for 200 million years. At 2.7m (almost 9ft) long, this fearsome reptile is well-known to be able to conquer any prey in its way. But the American alligator can also play nice: they dig huge “alligator holes” to retain water for refuge during dry periods. This becomes a vital source of water for fish, insects, snacks, and turtles to name a few.

However, the gathering of these creatures is a delicious food source for the American alligator—the circle of life. What may be less known about this species is that it can survive subzero temperatures. Using its biology to its advantage, the American alligator can stick its snout just above the surface level of the water, enough to breathe, while the water freezes around it.